Magnetic encoders are used in applications such as flow control, medical, aerospace, transportation, military, heavy equipment and computers. These magnetic encoders essentially convert mechanical rotary motion into electrical signals such as digital pulse streams.
The technology of magnetic encoders consists of a diametrically polarized magnet, imbedded into the end of a rotating shaft, positioned over a custom Application Specific Integrated Circuit (ASIC) sensor. When the magnet is rotated, the alternating polarities cause the multiple hall effect sensors on the integrated circuit sensor chip to output two sine waves ninety degrees out of phase with each other. This information is fed into a decoding and interpolation portion of the integrated circuit sensor chip with the resulting encoder output being either an incremental 2 bit gray code, or SSI serial output.
Prior art magnetic encoder devices have limited accuracy because of the placement and alignment of the diametrically polarized magnet to the sensor chip. Misalignment of the diametrically polarized magnet to the sensor chip may cause inaccuracies in the device of up to four hundred percent. Currently, there is a need in the art for a device to ensure the accurate alignment of the sensor chip to the diametrically polarized magnet. In addition, there is a need in the art for a magnetic encoder apparatus that contains the alignment device in a single housing.